TY  - CHAP
M1  - Book, Section
TI  - Hemopoiesis
A1  - Mescher, Anthony L.
Y1  - 2021
N1  - 
T2  - Junqueira's Basic Histology Text and Atlas, 16e
AB  - Hemopoiesis  SUMMARY  OF  KEY  POINTSPluripotent  stem  cells  for  blood  cell  formation,  or  hemopoiesis,  occur  in  the  bone  marrow  of  children  and  adults.Progenitor  cells,  committed  to  forming  each  type  of  mature  blood  cell,  proliferate  and  differentiate  within  microenvironmental  niches  of  stromal  cells,  other  cells,  and  ECM  with  specific  growth  factors.These  progenitor  cells  are  also  known  as  CFUs  and  the  growth  factors  are  also  called  CSFs  or  cytokines.Red  bone  marrow  is  active  in  hemopoiesis;  yellow  bone  marrow  consists  mostly  of  adipose  tissue.Erythropoietic  islands  or  cords  within  marrow  contain  the  red  blood  cell  lineage:  proerythroblasts,  erythroblasts  with  succeeding  developmental  stages  called  basophilic,  polychromatophilic,  and  orthochromatophilic  that  reflect  the  cytoplasmic  transition  from  RNA-rich  to  hemoglobin-filled.At  the  last  stage  of  erythropoiesis  cell  nuclei  are  extruded,  producing  reticulocytes  that  still  contain  some  polyribosomes  but  are  released  into  the  circulation.Granulopoiesis  includes  myeloblasts,  which  have  large  nuclei  and  relatively  little  cytoplasm;  promyelocytes,  in  which  lysosomal  azurophilic  granules  are  produced;  myelocytes,  in  which  specific  granules  for  one  of  the  three  types  of  granulocytes  are  formed;  and  metamyelocytes,  in  which  the  characteristic  changes  in  nuclear  morphology  occur.Immature  neutrophilic  metamyelocytes  called  band  (stab)  cells  are  released  prematurely  when  the  compartment  of  circulating  neutrophils  is  deleted  during  bacterial  infections.Monoblasts  produce  monocytes  in  red  marrow,  but  lymphoblasts  give  rise  to  lymphocytes  primarily  in  the  lymphoid  tissues  in  processes  involving  acquired  immunity.Megakaryocytes,  large  polyploid  cells  of  red  bone  marrow,  produce  platelets,  or  thrombocytes,  by  releasing  them  from  the  ends  of  cytoplasmic  processes  called  proplatelets.All  these  formed  elements  of  blood  enter  the  circulation  by  crossing  the  discontinuous  endothelium  of  sinusoids  in  the  red  marrow.  
SN  - 
PB  - McGraw Hill
CY  - New York, NY
Y2  - 2024/04/18
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1184200605
ER  -